This disclosure generally relates to valves, and more particularly, to contaminant resistant pressure regulating valves.
Some known valves incorporate matched diameter components with metering edges to resist buildup of contaminants that may be present in fluid passed through the valves. However, pressure and fluid flow forces may drive contaminants into clearances between the matched diameter components. Over time, such contaminants may accumulate in these sensitive clearances, which may bind the valves in the open or closed position, for example.
When the valves are open and flowing, the contaminants in the fluid stream may be directed into these clearances by fluid momentum and pressure deltas (i.e., pressure differences over a portion of the valves). When the valves are closed, the pressure deltas continue to drive contaminants into clearances such as diametrical clearances between a piston and a sleeve. In addition, the valves may include a metering edge that includes non-flowing areas, which may allow contaminants to remain in those non-flowing areas and build up over time. Accordingly, it is desirable to provide a self-cleaning, contamination resistant valve.